The present invention relates to a process for the separation of serotonine from coffee wax and also to processes for the preparation of certain derivatives of serotonine, more particularly N-acetyl serotonine, melatonine and mexamine.
Serotonine, the chemical name of which is 5-hydroxytryptamine, is an indolic alkaloid having the following formula: ##STR1##
This alkaloid plays an important role in the metabolism of the brain and has vasoconstrictor, antihypertensive and antiallergenic properties, and may be used for the treatment of psychoses, migraine and for the control of excessive smoking.
The derivatives of serotonine also possess pharmacological properties as follows:
N-acetyl serotonine, the chemical name of which is N-acetyl-5-hydroxytryptamine has antihypertensive properties.
Melatonine the chemical name of which is N-acetyl-5-methoxytryptamine, is secreted by the pineal gland and possesses a regulatory activity on the circadian cycle. In addition, its use in an amount of 1-2 mg/day can induce ovulation in sheep, which is of considerable economic importance. Moreover, it has been shown that melatonine can induce sleep in man in an amount of 1-3 mg/kg body weight.
Mexamine, the chemical name of which is 5-methoxytryptamine hydrochloride, has been proposed as a sedative and as a radioprotective agent.
In French Pat. Nos. 2333793 and 2371429 there is described a process for the separation of serotonine from coffee wax in which a solution of coffee wax in an alcohol is subjected to an alkaline hydrolysis using a strong base in an inert atmosphere, after which the reaction medium containing the serotonine is recovered. In French Pat. No. 2333793 the alcohols used are those insoluble or partially soluble in water having from 4 to 8 carbon atoms e.g. isobutanol, pentanols or hexanols. However the yield obtained is relatively low (8.6 grams serotonine per kilogram of wax) because only about 50% hydrolysis takes place. In French Pat. No. 2371429 the alcohol used is benzyl alcohol or one of its homologues but the yield is not increased because the alcohol forms the corresponding primary amine which is difficult to separate from the serotonine and, in addition, a .beta.-carboline is formed from serotonine which impairs the yield. We have now found, surprisingly, that by using certain glycols or glycol ethers as the solvent in a process similar to that described in the above-mentioned French Patents, a much more complete hydrolysis can be achieved without provoking the formation of amines and .beta.-carboline and leading to a yield about 3.5 times greater.